Hello everyone,
after posting the question “extension or new build” in another thread yesterday, and already leaning toward a new build, I’m now trying to make a “plan” for what I actually need to do...
My problem is knowing what step to take first.
Of course, I first need to find out whether I can even finance the project.
For that, the bank advisor wants to see a cost estimate for the project so they can tell me if it’s financially feasible.
To create a reasonably accurate cost estimate, I need a building plan and quotes.
But I can only get those once the architect knows the plot and the other conditions.
However, I don’t have the plot yet, so I don’t know its costs or the conditions.
It’s a bit of a catch-22.
Intuitively, I would say I estimate the costs as accurately as possible. That only works with a lot of reading, calculating, and thinking. But how do I tell good advice from bad?
I can fairly well narrow down what the plot will cost. Real estate portals like Immowelt and others offer plenty of information to estimate these costs. With €120,000 including all fees (property transfer tax, notary, soil analysis), I should be safe here in our region (Saarland)—if anything, a bit on the low side.
The additional construction costs were already well outlined in a related thread here—I should be fine with €50,000, judging from a quick read of that thread (I plan to study it more thoroughly once I get started).
But how do I arrive at a price for the house? Prefabricated house suppliers offer attractive prices, but something is always off with the example plans. And every change adds cost. On top of that, there are many negative reports about these prefab houses. This actually makes me want to work with a local architect I know, who I would potentially entrust with the whole project and its supervision. On the other hand, I worry whether such a “small” architect is really the best choice for me, or whether, due to other projects, they might not devote as much attention to my project as I expect...
I’ve gotten a bit off-topic—but these questions are really pressing for me.
Back to the main point: Rules of thumb like X€ per square meter or Y€ per cubic meter only provide a rough guideline. When I include features like a granny flat, garage, and so on, I can’t seem to come up with a number I, as a complete layperson, can really “understand.”
If I calculate, say, 250m² (2700 sq ft) of living space at €2000 per m² (€185 per sq ft), I’m already at €500,000 excluding the plot, additional construction costs, or anything else. That sounds excessive for a detached house with a granny flat...
If I calculate based on a footprint of 10 × 14m (33 × 46 ft), two full floors (each 3m (10 ft) high), and a standard pitched roof (1.5m (5 ft) average height), I get 10 × 14 × (2 × 3 + 1.5) = 1050m³ (37,100 ft³) of enclosed volume, which, at €400 per m³ (€11 per ft³), comes to €420,000. That still sounds like a lot for a detached house with a granny flat, right?
Considering that a bathroom, at €25,000, is probably the “most expensive” room (I have an offer for the extension we once planned), I can’t imagine the house costing 20 times that amount!
I’m looking for someone, preferably several people, who can guide me step by step and show me how to approach this.
The more blogs, forums, and pages I read, the more confused I get. That’s why I’m creating this own thread here, hoping it will lead me to the goal—or at least show me the way...
Best regards,
Xorrhal & Family
after posting the question “extension or new build” in another thread yesterday, and already leaning toward a new build, I’m now trying to make a “plan” for what I actually need to do...
My problem is knowing what step to take first.
Of course, I first need to find out whether I can even finance the project.
For that, the bank advisor wants to see a cost estimate for the project so they can tell me if it’s financially feasible.
To create a reasonably accurate cost estimate, I need a building plan and quotes.
But I can only get those once the architect knows the plot and the other conditions.
However, I don’t have the plot yet, so I don’t know its costs or the conditions.
It’s a bit of a catch-22.
Intuitively, I would say I estimate the costs as accurately as possible. That only works with a lot of reading, calculating, and thinking. But how do I tell good advice from bad?
I can fairly well narrow down what the plot will cost. Real estate portals like Immowelt and others offer plenty of information to estimate these costs. With €120,000 including all fees (property transfer tax, notary, soil analysis), I should be safe here in our region (Saarland)—if anything, a bit on the low side.
The additional construction costs were already well outlined in a related thread here—I should be fine with €50,000, judging from a quick read of that thread (I plan to study it more thoroughly once I get started).
But how do I arrive at a price for the house? Prefabricated house suppliers offer attractive prices, but something is always off with the example plans. And every change adds cost. On top of that, there are many negative reports about these prefab houses. This actually makes me want to work with a local architect I know, who I would potentially entrust with the whole project and its supervision. On the other hand, I worry whether such a “small” architect is really the best choice for me, or whether, due to other projects, they might not devote as much attention to my project as I expect...
I’ve gotten a bit off-topic—but these questions are really pressing for me.
Back to the main point: Rules of thumb like X€ per square meter or Y€ per cubic meter only provide a rough guideline. When I include features like a granny flat, garage, and so on, I can’t seem to come up with a number I, as a complete layperson, can really “understand.”
If I calculate, say, 250m² (2700 sq ft) of living space at €2000 per m² (€185 per sq ft), I’m already at €500,000 excluding the plot, additional construction costs, or anything else. That sounds excessive for a detached house with a granny flat...
If I calculate based on a footprint of 10 × 14m (33 × 46 ft), two full floors (each 3m (10 ft) high), and a standard pitched roof (1.5m (5 ft) average height), I get 10 × 14 × (2 × 3 + 1.5) = 1050m³ (37,100 ft³) of enclosed volume, which, at €400 per m³ (€11 per ft³), comes to €420,000. That still sounds like a lot for a detached house with a granny flat, right?
Considering that a bathroom, at €25,000, is probably the “most expensive” room (I have an offer for the extension we once planned), I can’t imagine the house costing 20 times that amount!
I’m looking for someone, preferably several people, who can guide me step by step and show me how to approach this.
The more blogs, forums, and pages I read, the more confused I get. That’s why I’m creating this own thread here, hoping it will lead me to the goal—or at least show me the way...
Best regards,
Xorrhal & Family
So our architect is estimating 400€ per cubic meter, which means for 132m² (1,420 sq ft) plus a basement, the total comes to 350,000€.
So yes, the figures are accurate. It doesn’t make sense to manipulate the numbers to look better. If there is money left over, great; if not, then that’s just how it is.
So yes, the figures are accurate. It doesn’t make sense to manipulate the numbers to look better. If there is money left over, great; if not, then that’s just how it is.
If I estimate too high, the financing might not be possible. Also, you have to provide documentation to actually receive the money from the construction loan. I can’t just say at the end, "Oops, 75,000€ left – I’ll buy a car and take a trip to the Maldives."
And estimating too low should be avoided anyway, since additional financing is usually much more expensive, if you can even get it at all. Or am I mistaken?
I’m not trying to sugarcoat the numbers. If they are correct, they are correct. I just find it hard to imagine…
Your calculation of 400€/m³ would come close to my estimate above of 420,000€. Assuming I can fit my 230m² (2,475 sq ft) of living space into a 10 by 14 meter (33 by 46 feet) footprint over two floors. Of course, that would leave out the basement and/or garage – although I tend to prefer a larger utility room instead of a basement, and a larger garage. Would 500,000€ then be realistic? Plus the plot of land, plus additional construction costs, plus a contingency?
And estimating too low should be avoided anyway, since additional financing is usually much more expensive, if you can even get it at all. Or am I mistaken?
I’m not trying to sugarcoat the numbers. If they are correct, they are correct. I just find it hard to imagine…
Your calculation of 400€/m³ would come close to my estimate above of 420,000€. Assuming I can fit my 230m² (2,475 sq ft) of living space into a 10 by 14 meter (33 by 46 feet) footprint over two floors. Of course, that would leave out the basement and/or garage – although I tend to prefer a larger utility room instead of a basement, and a larger garage. Would 500,000€ then be realistic? Plus the plot of land, plus additional construction costs, plus a contingency?
Our architect calculated €325 per m³ (approximately $350 per cubic yard) for the residential building and €175 per m³ (approximately $190 per cubic yard) for the garage. Plus additional costs. Plus landscaping. Plus the land, etc... But this includes all "special features" such as electric shutters everywhere, some venetian blinds, a ventilation system, colored windows, and so on. Currently, we are still under construction, but except for some flooring and landscaping—which are roughly planned—the entire selection and decisions are finalized. We are currently at the rough installation stage for electrical, plumbing, and ventilation; the structural shell is therefore completed. I have to say, at the moment it looks like we will actually hit the mark, and the architect’s rough cost estimate will fit perfectly.
We are building 160 m² (about 1,700 sq ft) plus a large double garage. However, we are building in an affordable rural region (Rhineland-Palatinate, Germany). These prices are probably no longer achievable elsewhere, at least not if you want to go beyond standard finishes.
Regarding the sequence: First, we went to our house bank and had a basic advisory discussion. We explained how much monthly payment we were considering, and based on that, they gave us a rough loan amount that, in their opinion, would be easily possible. Since that amount corresponded quite well with our own preliminary budget and the desired house (calculated simply as x m² times x €), we then searched for an architect and discussed our wishes and ideas with him. He then produced the above calculation with €325 per m³. After that, we planned the entire house with him. He obtained bids for the individual trades for the planned house and subsequently gave us a detailed cost breakdown based on the actual offers from the companies involved, which roughly matched the previous rough estimate per m³ (or was even slightly lower). With this, we went back to the bank, applied for the loan including a small buffer, and then construction began. As mentioned, it currently looks like it will match exactly (within €1,000 / around $1,050). But, of course, this could be very different in other regions or with different requirements.
We are building 160 m² (about 1,700 sq ft) plus a large double garage. However, we are building in an affordable rural region (Rhineland-Palatinate, Germany). These prices are probably no longer achievable elsewhere, at least not if you want to go beyond standard finishes.
Regarding the sequence: First, we went to our house bank and had a basic advisory discussion. We explained how much monthly payment we were considering, and based on that, they gave us a rough loan amount that, in their opinion, would be easily possible. Since that amount corresponded quite well with our own preliminary budget and the desired house (calculated simply as x m² times x €), we then searched for an architect and discussed our wishes and ideas with him. He then produced the above calculation with €325 per m³. After that, we planned the entire house with him. He obtained bids for the individual trades for the planned house and subsequently gave us a detailed cost breakdown based on the actual offers from the companies involved, which roughly matched the previous rough estimate per m³ (or was even slightly lower). With this, we went back to the bank, applied for the loan including a small buffer, and then construction began. As mentioned, it currently looks like it will match exactly (within €1,000 / around $1,050). But, of course, this could be very different in other regions or with different requirements.
The figures are approximate. The prices per m² (net usable floor area) refer to a "standard" level of finishing. For the price per m³, €320-380 can be assumed. Additional construction incidental costs of 18-22% apply. Not included in these costs are cost group 200 (site preparation and development / public and private utility connections, demolition, site clearing), 500 (external works, garage, etc.), and 600 (interior fittings, lighting, kitchen).
With 10m x 14m (these are exterior dimensions), you have approximately 102m² (1,098 sq ft) per floor. This means you still need to account for the exterior walls to reach your desired 230m² (2,476 sq ft).
For example, we are building on 11m x 8.25m = 90.75m² (977 sq ft), but depending on the number and thickness of the walls, the usable living area per floor is only about 67m² (721 sq ft). This results in a factor of 1.37.
So, you would need to build on 11.25m x 14m (37 ft x 46 ft).
For example, we are building on 11m x 8.25m = 90.75m² (977 sq ft), but depending on the number and thickness of the walls, the usable living area per floor is only about 67m² (721 sq ft). This results in a factor of 1.37.
So, you would need to build on 11.25m x 14m (37 ft x 46 ft).
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